To better study the toxicity at the MTD of the stereotactic boost, there was a 10 patient expansion cohort.The primary endpoint of the phase II portion of the study was two-year local failure rate of the protocol treatment. Local failure was defined as biopsy-proven recurrent disease, or if a biopsy was not attainable, by increasing FDG-avidity on PET-CT on 2 consecutive scans at least 1 month apart. Based on prior studies, a 2-year local failure rate of 15% would be worthy of further study, while a 2-year local failure rate of 35% would not justify further utilization of the treatment. With 32 eligible patients on this study, the treatment will be deemed promising if at least 25 patients are free of local failure at 2 years. Using this design, there was an 8% probability of declaring the treatment worthy of further study if the true 2-year local failure rate was 35%, and a 90% probability of declaring the treatment worthy of further study if the true 2-year local failure rate was 15% by using a one-sided one-sample exact binomial test.